The present invention relates to a continuous label paper, for providing labels having a back side coated with an adhesive, and prepared from continuous paper lengths consisting of a label sheet provided with label pieces and a support sheet, detachably attached to the back side of the label sheet, and it also relates to a method to prepare it.
In the conventional type of continuous label paper, a continuous label sheet with an adhesive backing is provided, and a support sheet is attached by the adhesive in a detachable manner on the back side of the label sheet, and a portion of the label paper is provided with transfer holes at equal spacings along both lateral sides. Perforation lines are provided in the label sheet other than the portion with transfer holes in order to form label pieces, which can be removed from the label sheet and attached to envelopes and other articles with different information and data such as addresses, product numbers, product names, etc. The transfer holes of said continuous label paper engage with the tractor pins of a printer connected to a computer, and address information, delivery data, etc. are printed on said label pieces by moving said continuous label paper through the printer.
In such a conventional continuous label paper, however, when printing is performed on a large quantity of continuous label paper, especially when a non-impact printer which prints by means of toner is used, adhesive coming out of the transfer hole of the continuous label paper sticks on and is accumulated on and around the tractor pins of the printer and often contaminates the photosensitive drum, thus adversely affecting the movement of subsequent continuous label paper.
To overcome such disadvantage, a type of continuous label paper is known where the transfer holes are not provided in the label sheet in order to prevent the adhesive from coming out of the transfer holes. However, in preparing continuous label paper of such type, the toner on the surface of the photosensitive drum of the non-impact printer is attached to the portion of the detachment sheet with the transfer holes, which is exposed because the transfer holes are eliminated from the label sheet. Since the toner is further attached and accumulated in zonal form on the fixed roller or other parts of the non-impact printer, it frequently causes the jamming of continuous label paper. Zonal contamination often occurs when continuous label papers having different widths are used.
In order to eliminate all such disadvantages, a new type of continuous label paper 100 has been proposed (Japanese Utility Model Publication Sho 61-41105). As shown in FIGS. 7(a) to (d), the continuous label paper consists of supporting sheet 103 detachably mounted on the back side of the label sheet 102 coated with adhesive 101, and the transfer holes 104 are provided along both lateral sides of supporting sheet 103 at equal spacings. Both lateral sides of the label sheet are formed in an uneven and irregular shape so that the label sheet 102 does not come into contact with the transfer holes 104 and it reaches the lateral edge of the continuous label paper only by projecting portions 102b between transfer holes 104.
To prepare continuous label paper 100, it is necessary to have a process to detach an external portion of the label sheet, which initially overlies the position of the transfer holes 104 at the time of assembly of the sheets and which is not needed in the finished label paper because both lateral edges of the label sheet 102 are shaped in an uneven and irregular form.
However, if the width of the label paper is as is shown by solid lines in FIG. 7, the external portions 102a of the label sheet overlying the positions of the transfer holes 104, as shown in FIG. 7(c), and not needed, are not continuous in the longitudinal direction of the label paper but separated from each other. Accordingly, it is not possible to efficiently detach the external portions 102a of the label sheet 102 in a continuous manner.
There is a method to exclude such disadvantages. As shown by dot-dash lines in FIG. 7(a), it has been proposed to make the width of the sheets making up the continuous label paper wider at first. After the unnecessary portions 102a of the label sheet 102, including the added width portion, are detached by simply peeling them away as a continuous strip 102c, shown in FIG. 7(d), the added width portion 103a of the remaining supporting sheet 103 is removed by cutting it off to make the label paper the width originally desired.
Even with this method, however, there exist in the strip 102c wide portions (the portions complementary to where the label sheet 102 is recessed to match the transfer holes 104) and the very narrow portions (the portions complementary to where the label sheet 102 protrudes), and the strip 102c is often torn off at this very narrow portion during the peeling off of the strip. Because the unnecessary portions 102a on both sides are independent from each other, the continuity of the strip 102c of the unnecessary portions of the label sheet 102 is lost if these are torn, and smooth peeling away is thus hindered.
In the transfer system for the label paper, where the printing paper is transferred by bringing it into contact with a preheated board through suction in order to fix the toner after toner is deposited by a non-impact printer of the xerography type, smooth printing is not achievable because of poor air penetration when the label paper has a three-layer structure consisting of a label sheet, adhesive, and a detachment sheet. Specifically, excessive suction occurs during the transfer operation of the printer, and smooth movement is not accomplished because the resistance to movement in the transfer direction is increased. In addition, toner often falls off due to excessive contact and contaminates the interior of the printer.